1. Field of the Invention
The present invention relates to a film connecting/feeding apparatus to be incorporated into a wrapping system. More particularly, the invention relates to a film connecting/feeding apparatus which makes it possible to continuously feed a film by connecting a trailing end of a film delivered from a film roll and a leading end of a spare film roll.
2. Description of the Related Art
Conventionally known film connecting/feeding apparatuses of this type include those disclosed in Japanese Unexamined Patent Application Publications Nos. 4-338056, 6-278921, 5-97122, and 5-112326. 
Among others, Japanese Unexamined Patent Application Publications Nos. 4-338056 and 6-278921 disclose conventional apparatus having features in a conveying unit of the film roll.
As shown in FIG. 17, the web feeding apparatus 200 (film connecting/feeding apparatus) in 4-338056 comprises a rewinding position 202, a standby position 204 and a feeding position 205, and has a configuration in which the trailing end of a web 201a delivered from a web roll 201 held at the rewinding position 202 and the leading end of a web 203a delivered from a spare web roll 203 held at the standby position 204 are connected at the connecting position 205.
The web feeding apparatus 200 has an annular driving belt 206 travelling around between the rewinding position 202 and the standby position 204, and three bearings 207 are attached to the annular driving belt 206 at equal intervals. These bearings 207 can rotatably support web rolls, respectively.
When one 207 of these bearings 207 is moved to the rewinding position 202 and arranged there, another bearing 207 is moved to the standby position 204 and arranged there. The remaining bearing 207 is in standby at the middle among the positions.
As shown in FIG. 18, the web connecting/feeding apparatus 300 disclosed in Japanese Unexamined Patent Application Publication No. 6-278921 has swinging levers 304 and 305. One 304 of the levers rotatably holds a spare web roll 303a at the tip thereof, and the other lever 305 rotatably holds a delivery web roll 303b. The levers 304 and 305 are driven by driving mechanisms 306 and 307, respectively.
When all the web is delivered from the delivery web roll 303b, the lever 305 swings counterclockwise in FIG. 18, and excludes the roll core remaining at the tip of the lever 305. Subsequently, the levers 304 and 305 oscillate in synchronization, and the web roll 303a held at the tip of the lever 304 is passed to the tip of the lever 305.
Japanese Unexamined Patent Application Publications Nos. 5-971122 and 5-112326 disclose conventional apparatuses characterized by spare film leading end holding means at a connecting position.
The automatic connecting apparatus of a wrapping film disclosed in 5-97122 has a configuration in which the leading end of a film is held by vacuum sucking to bring the same into standby at the connecting position.
The paper connecting apparatus disclosed in 5-112326 has a configuration in which the leading end of a web is held by means of an adhesive tape to bring the same into standby at the connecting position.
As described above, the web feeding apparatus disclosed in Japanese Unexamined Patent Application Publication No. 4-338056 has a configuration in which the bearing 207 is provided directly on the annular driving belt 206 travelling around between the rewinding position 202 and the standby position 204, and the web rolls 201 and 203 are held at the individual positions 202 and 204 by means of this bearing 207. The bearing 207 rotatably supporting the web rolls should have a strong structure capable of withstanding the load and rotating force of the web rolls.
A plurality of such bearings 207 having a strong structure as described above are necessary. In addition, in order to support these bearings 207 by an annular driving belt 206 such as a chain or a belt, it is necessary to impart a strength sufficient to resist to the action of a considerable load to the annular driving belt 206. Comprehensive satisfaction of these requirements poses a problem of a very high manufacturing cost.
Also in the web connecting/feeding apparatus 300 disclosed in 6-278921, provision of driving sections 306 and 307 for the levers 304 and 305 holding the web roll leads to troublesome control and poses the problem of a high manufacturing cost of the apparatus.
In the apparatus disclosed in 5-97122 and 5-112326, the film (web) leading end is held at the connecting position by an adhesive tape or vacuum sucking. These holding means use a large holding force in general acting on the film. This may cause a positional shift of the film from the delivery track when stripping off the film from the connecting position after connection of the film, thus impairing stable continuous delivery of the film.
The present invention was developed in view of these circumstances, and has an object to ensure stable continuous delivery of the film with a low manufacturing cost.
To achieve the above-mentioned object, the film connecting/feeding apparatus has a configuration in which there are set a delivery position where a delivery film roll is held; a standby position where a spare film roll is held; and a connecting position where a leading end of a film delivered from the spare film roll is held, and the leading end and a film delivered from the delivery position are connected; the apparatus comprising delivery supporting means, provided at the delivery position, which rotatably supports the axial core of a delivery film roll, and standby supporting means, provided at the standby position, which supports the axial core of the spare film roll; and an endless belt member which is put around a rotary member and circumferentially travels, and roll conveying means which comprises a conveying member which is attached to this endless belt member, and holds the axial core of the film roll; wherein the roll conveying means receives a spare film roll by means of the conveying member from the standby supporting means, conveys the film roll to the delivery position, and passes the same to the delivery supporting means.
According to the present invention in which there are provided delivery supporting means and standby supporting means which support the film roll, respectively, at the delivery position and the standby position, the necessity is eliminated to impart a function for supporting the film roll to the roll conveying means accounting for a particularly large ratio among items of parts cost of the apparatus. It is therefore possible to achieve a simpler configuration of the roll conveying means and thus to reduce the manufacturing cost for the apparatus as a whole.
Since the roll conveying means has a configuration in which the endless belt means is wound around the rotary members and the conveying member is attached to this endless belt member, it is possible to cause a circumferential movement of the conveying member by the rotational driving force by rotating the rotary member with a single driving source. It is not therefore necessary to provide a plurality of driving sources, thus permitting reduction of the number of driving sources, leading to a lower cost of the apparatus.
The film connecting/feeding apparatus of the invention may further comprise a discharge path for discharging the axial core having delivered the film; wherein the conveying member of the roll conveying means further receives an axial core having delivered the film, remaining at the delivery position from the delivery supporting means, and conveys the same to the discharge path.
According to this configuration, an axial core of which the film has been delivered to the delivery position never remains, and it is thus possible to pass a film roll without any trouble to the delivery supporting means by the conveying member.
The apparatus of the invention may have a configuration in which an operating board is attached to the apparatus main body so as to be opened and closed; a holding member which holds an inserted folded portion formed by folding the leading end of the film delivered from the standby position, with a side of the operating board as an operating surface is attached to the operating surface; and in the closed state of the operating board, the holding member is positioned at the connecting position.
According to this configuration, the holding member holding the leading end of the film delivered from the standby position can be positioned at the connecting position in the closed state of the operating board. It is therefore possible to accurately position the leading end of the film and stably accomplish connection with the film delivered from the delivery position.
Because the folded portion formed by folding the leading end of the film is held by inserting the same into the holding member, it is possible to prevent occurrence of a positional shift of the film as a result of easy trip of the leading end of the film from the holding member upon delivery after film connection.
The apparatus of the invention may have a configuration in which an operating position for carrying out an operation of folding the leading end of the film delivered from the standby position and causing the holding member to hold the folded position is set on the front side of the apparatus main body; and the operating board is arranged so that, in the opened state, the operating surface is placed upward at the operating position.
According to this configuration, it is possible to cause the holding member to easily hold the leading end of the film at the operating position, and improve operability thereof.
The apparatus of the invention may have a configuration in which an edge positioning section which guides edges on both sides of the film delivered from the standby position is formed on the operating surface of the operating board.
According to this configuration, it is possible to easily accomplish positioning of both edges of the film.
The apparatus of the invention may have an operating board made of a transparent material. By adopting this configuration, even when the operating board is closed, it is possible to easily confirm the internal state of the apparatus, thus permitting easier maintenance control.
The apparatus of the invention may have a configuration in which a feeding position at which the film roll is fed to the standby position, a discharge position set at the terminal end of the discharge path, and the operating position are arranged in the height direction on the front side of the apparatus main body.
In this configuration, the operation of feeding the film roll, the operation of holding the leading end of the film by the holding member, and the operation of removing the axial core after delivery of the film can be conducted on the front side of the apparatus main body, thus permitting remarkable improvement of operating efficiency.
The apparatus of the invention may have a configuration in which the apparatus comprises end detecting means which detects the end of the film delivered from the delivery position at a prescribed detecting position; and connecting position aligning means which delivers the end portion of the film of which the end has been detected by the end detecting means to the connecting position in response to the distance between the detecting position and the connecting position.
By adopting such a configuration, it is possible to achieve a wrapping loss under a pitch of wrapping bag during connection with the spare film, thus permitting minimization of wrapping loss.
The apparatus of the invention may have a configuration in which the apparatus comprises registration mark detecting means which detects a registration mark attached to the film delivered from the delivery position at a prescribed position; wrapping length storing means which stores a wrapping length set on the film delivered from the delivery position; and registration mark aligning means which aligns a registration mark position of a film of which the end has been detected by the end detecting means and of which the registration mark has been detected by the registration mark detecting means with the registration mark position of a film of which the leading end portion has been held at the connecting position, on the basis of a wrapping length stored in the wrapping length storing means and the distance between the registration mark detecting position and the connecting position.
According to this configuration, for various films of different wrapping lengths, it is possible to carry out pattern alignment automatically simultaneously with connection of films with reference to registration mark, thus improving operability.